1. Field of the Invention
The present invention relates to a device for inputting characters by handwriting for forming a document by extracting a handwritten character and thereafter recognizing the character.
2. Description of the Background Art
Conventionally, as a device for inputting characters by handwriting, there have been such devices as disclosed in Japanese Patent Laid-Open Publication Nos. HEI 4-199485 and HEI 5-197477. In those devices, a special handwriting input frame is always displayed in a specified position on a transparent tablet, or a character input board having a special handwriting input frame is displayed in a popping-up manner in a specified position on a screen when a handwriting input mode is selected.
The "character input device" disclosed in Japanese Patent Laid-Open Publication No. HEI 4-199485 is comprised of a position input unit, a processing control unit, a display unit and an external storage unit. Then by displaying a character input board including a character input frame of specified dimensions on the display unit when a character input mode is selected, a character is allowed to be inputted by handwriting consistently in a specified size regardless of the size of a character input item.
In the "handwriting information device" disclosed in Japanese Patent Laid-Open Publication No. HEI 5-197477, by displaying a character input screen provided with a handwriting guide line in the character input frame and operating a layout changing means, the size of the character input frame and a handwriting guide line are set for layout in an arrangement most appropriate for the operator's sense of use.
In either of the cases, after completion of character recognition, each character inputted by handwriting in the character input frame is displayed in the character input frame, an independently determined position, or an arbitrary position designated by the operator in a printing type form.
There is a further device for inputting characters by handwriting as disclosed in Japanese Patent Laid-Open Publication No. SHO 61-243582.
In the "device for inputting characters by handwriting" disclosed in Japanese Patent Laid-Open Publication No. SHO 61-243582, a valid input area setting means sets a valid input area by enlarging an input area frame in which the existence of a tip end of an input pen is detected among a specified number of input area frames set on a tablet. If there are traces of a character existing in the set valid input area, the character is detected as an input character to the input area frame even when the character is jutting out of the input area frame.
The prior art devices for inputting characters by handwriting have problems as follows.
(1) Problems of the devices for inputting characters by handwriting disclosed in Japanese Patent Laid-Open Publication Nos. HEI 4-199485 and HEI 5-197477.
As described above, the special handwriting input frame is displayed in a specified position on the transparent tablet. Therefore, the position in which a is handwriting input can be effected is limited, and further the position in which a printing type is displayed as a result of recognition or extraction differs from the position in which the character input is effected by handwriting. Consequently, the operator cannot write each character either in a position in which the operator easily writes the character or in the position in which the operator desires to input or display the character on the tablet. Therefore, the operator feels far differently from his or her feeling in handwriting a character on an ordinary notebook or the like, meaning that a natural-touch handwriting input cannot be effected.
Furthermore, it is required to execute an operation of cancelling, for example, the character input mode in erasing the special handwriting input frame displayed on the transparent tablet, and this also results in a very troublesome handwriting character input.
(2) Problems of the device for inputting characters by handwriting disclosed in Japanese Patent Laid-Open Publication No. SHO 61-243582.
As described above, the specified number of input area frames are set on the tablet. The above naturally results in limitation of the area in which the input area frames can be set on the tablet, so that the area of the tablet cannot be effectively utilized.
Furthermore, in spite of the advantage that correct character recognition can be effected even though the traces of handwriting by the input pen are jutting out of the input area frame, a sufficient effect cannot be achieved unless the valid input area is set according to character handwriting trace conditions such as specification of the position of the input area frame in which the tip end of the input pen is located, start position coordinates of the character handwriting trace and coordinates in the middle of a stroke drawn continuously by the input pen operated without being out of contact with the tablet.
(3) Common problems of the conventional systems
When successively inputting characters by handwriting, it is common to operate an adopting button, an inserting button or the like every time each character is repetitively hand written in a fixed character input frame to thereby insert a printing type that is a result of recognition (or a result of extraction) into a position in which the printing type is desired to be inputted. However, in such a case, the character input position is fixed. Therefore, when the character input position is located apart from the printing type inserting position, it is impossible to effect character input while recognizing the previously inputted character. Furthermore, it is required to execute a character inserting operation every time a character is inserted, and it can be said that this is different from natural notetaking.
FIG. 33 shows an exemplified display screen of a conventional device for inputting characters by handwriting, while FIGS. 34A through 34D show an exemplified operation of the device. A character input frame 1 is set in a character input board 2. The character input board 2 is opaque. Therefore, when the character input board 2 is displayed on printing types which have been already displayed in a manner as shown in FIG. 34A, the printing types are hidden behind the character input board 2 as shown in FIG. 34B. On the character input board 2, there are further set editing buttons 3 for such functions as deletion, adoption and input for use in inserting a character after recognition. Therefore, as shown in FIGS. 34B and 34C, a range of setting of the character input frame 1 is limited by the editing buttons 3.
It cannot be said that the above arrangement can assure a natural-touch handwriting input as in handwriting a character on an ordinary notebook.
In conventional devices for inputting characters by handwriting, the size of each cell of the character input frame displayed on the transparent tablet is generally fixed. In view of the above, according to the device for inputting characters by handwriting disclosed in Japanese Patent Laid-Open Publication No. HEI 5-197477, the size of the character input frame and the number of handwriting guide lines can be changed by operating a layout changing means. However, this function is to set them for layout after a character input frame of a specified size and a specified number of handwriting guide lines are displayed, meaning that neither a character input frame of which size has been preparatorily set nor handwriting guide lines set in amount to an arbitrary number can be displayed in a popping-up manner.
In order to achieve a natural-touch handwriting input in view of the device for inputting characters by handwriting in which the character input frame is displayed on the transparent tablet, a character recognizing device with frame-free handwriting input has been already proposed. However, in the case of this character recognizing device, there arises another problem that a character recognition error tends to occur due to erroneous character extraction because no frame is provided for the handwriting input.